Radial tunnel syndrome

• condition presents with similar lateral elbow pain to lateral epicondylitis; however the site of maximal pain lies 4 finger breadths distal to the common extensor origin
  
  
• condition is caused by entrapment of the posterior interosseus nerve within the radial tunnel
  • posterior interosseus nerve is a branch of the radial nerve. It is a pure motor nerve with no sensory component, hence - unlike other entrapment neuropathies - there is no pins and needles or sensory deficit
  • there may be weakness of digital extensors

Investigation

• radial tunnel syndrome is a clinical diagnosis and should be considered in patients presenting with resistant lateral epicondylitis
• nerve conduction and electromyography studies have high specificity but low sensitivity

Management

• involves avoidance of aggravating factors and physiotherapy
• resistant cases should be referred for surgical decompression of the radial tunnel

Reference:

Wolf J et al. Radial Tunnel Syndrome: Review and Best Evidence. J Am Acad Orthop Surg. 2023 Aug 1;31(15):813-819